Alpha-Fetoprotein: The effect of both human and rat sources of this protein and their complexes with specific fatty acids will be individually investigated as to their effects of mitogen induced lymphocyte transformations, (human and rat), antibody formation (rats) and tissue graft retention (rat). Studies will be continued on the structure of human source protein to define a model of the molecule and its relation to serum albumin. Metalloproteins: Some preparations of bovine superoxide dismutase have extremely low E265-655 nM absorption ratios. The relatively high absorption at 655 nM suggests the presence of a prosthetic group or a labile structure which absorbs at this wave length. Attempts will be made to resolve this question. The human fetal extracts used to prepare alpha-fetoprotein will be used to generate metallothionine in studies designed to explain the shifts with age of this protein being complexed initially only with copper to one predominantly carrying cadmium. The relationships of metallothionine to chelatin will be investigated. Immunoglobulins: Studies of the serological properties of human lambda-chains as they relate to primary structural variations will be continued. Attempts to correlate these properties with any tendency to amyloid formation will be made.